Pressure reducers are already known from the prior art. These devices are pressure valves or throttle valves which are installed in an existing media conducting system, i.e. they have an inlet side and an outlet side for the corresponding medium (generally gas, in particular air). In this respect, the object of pressure reducers is to ensure that, irrespective of the pressure which is prevailing on the inlet side, a permissible operating pressure on the outlet side is not exceeded. In practice, this is usually achieved by continuously measuring the pressure on the outlet side. In this respect, as the pressure increases on the outlet side, the valve is closed to an increasing extent until finally the valve is fully closed when the permissible operating pressure has been reached. Thus, in most cases, this is a safety measure and is therefore used, for example, when high system pressures are to be reduced to pressures which are required for the workplace.
Vehicle seats which have various suspension or damping options to provide the user with the greatest possible sitting comfort are also known. Thus, for example, air-assisted horizontal and vertical suspension systems can be arranged in the seat. Air-assisted systems which are arranged in the seat or in the backrest as an additional cushion are also known, these cushions being intended to support or massage the anatomy of the user, such as the lumbar portion of the spine or the gluteal muscles. The vertical deflection of the seat can be controlled, for example by a pneumatic spring and by an additionally applied damper. It goes without saying that the pressures prevailing in the mentioned systems substantially affect the suspension characteristics and damping characteristics thereof.
In this respect, the weight of the user of the seat is essential. If a driver sits on the hitherto unused seat, the system pressure in the seat increases (controlled by the level control) and thereby the pressure in the pneumatic spring increases which, for example is arranged vertically between the seat and the vehicle floor. This system pressure increases further if a relatively heavy driver sits on the seat, instead of a light driver. At the same time, due to his lower weight, the light driver requires less pressure in air-assisted systems than a heavy driver.
An adaptation of the system pressure which is possible with respect to the weight of the occupant is achievable due to level-control valves which, in the case of a vehicle seat, ensure that the system pressure is adjusted depending on the driver's weight. However, if the other systems are to be adjusted depending on the prevailing system pressure so that the ratios of the two pressures, i.e. the system pressure and the pressure in the other system, for example in the horizontal suspension, correspond to a predetermined proportionality factor, then for example a throttle valve cannot be used, because by using a throttle valve, only a specific equal pressure can ever be adjusted, but the value thereof cannot be automatically equalised in proportion to the value of the reference pressure. Therefore, a device for the automatic, proportional adaptation of air-assisted systems to different driver weights by pressure reduction is hitherto unknown from the prior art.